Safety device for a motor vehicle seat

ABSTRACT

In order a safety device for a motor vehicle seat having a seat cushion part and a backrest, the backrest having a frame, a backrest cover, which faces rearward as seen in the direction of travel, and padding which faces forward, as seen in the direction of travel, and an airbag module is integrated into the backrest, said airbag module being arranged in that region of the backrest which faces the side wall structure of the motor vehicle in such a manner that an airbag is deployed when there is an impact between a driver and the side wall of the motor vehicle, said safety device ensuring a reliable and reproducible emergence of the airbag, it is proposed to arrange the airbag module to the rear of the backrest frame, when looking from the side wall of the motor vehicle.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a national phase of International Patent ApplicationNo. PCT/EP02/08456, filed Jul. 30, 2002, designating the United Statesof America, and published in German as WO 03/013915, the entiredisclosure of which is incorporated herein by reference. Priority isclaimed based on German Patent Application No. 101 37 634.0, filed Aug.3, 2001.

BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a safety device for a motor vehicle seat.

Safety devices of this type are known, for example, from the utilitymodel DE 200 17 919 U1. They are suitable for a motor vehicle seathaving a seat cushion part and a backrest. The backrest has a frame, abackrest cover, which faces rearward as seen in the direction of travel,and padding which faces forward, as seen in the direction of travel. Anairbag module is integrated into the backrest and is arranged in thatregion of the backrest which faces the side wall structure of the motorvehicle. The airbag is deployed when there is an impact between a driverand the side wall structure of the motor vehicle, for example theB-pillar and/or the side door.

In the known safety device, the airbag module is arranged between theframe and the backrest cover, so that it is placed to the rear of thebackrest cover and in front of the frame, as seen from the side wallstructure. An airbag outlet opening is provided in the region in whichthe backrest cover and padding butt against each other. This knownarrangement has the disadvantage that, if there is a side impact,structural parts penetrating the interior of the motor vehicle mayjeopardize the interference-free emergence of the airbag. This situationmay occur, for example, if the penetrating parts butt against thebackrest cover and deform it, and the airbag outlet opening is thusconcealed or the airbag module arranged to the rear of the backrestcover is damaged. Deformation of the backrest cover is possible, sincethe backrest cover serves to line the motor vehicle seat and istherefore not of sufficiently stable design.

Against this background, it is the object of the present invention todevelop a safety device in such a manner that reliable and reproducibleemergence of the airbag is ensured.

This object is achieved according to the invention by a safety devicefor a motor vehicle seat that includes a seat cushion part, a backresthaving a frame, a backrest cover, which faces rearward as seen in thedirection of travel, and padding which faces forward, as seen in thedirection of travel. The safety device includes an airbag module thathas an airbag, and the airbag module is integrated into the backrest andarranged in a region of the backrest which faces a side wall structureof the motor vehicle. The airbag module 11 is at least partiallysurrounded the frame 5 and is arranged to the rear of the frame 5 whenlooking from the side wall structure of the motor vehicle.

Accordingly, the invention is distinguished by the fact that the airbagmodule is arranged, as seen from the side wall structure, to the rear ofthe backrest frame—i.e. to the rear of its supporting part in thebackrest. The effect of this arrangement is that the airbag module isshielded against forces acting from the direction of the side wallstructure. In addition, an airbag outlet opening can be effectivelyprotected against penetrating structural parts and it can therefore beensured that the opening is always free for an airbag to emerge. Thebackrest frame is preferably designed in such a manner that virtually nodeformation occurs. In the event of a lateral application of force, theentire backrest together with the seat cushion part is rather displacedin the direction of the center of the motor vehicle than the frame islastingly deformed. A backrest frame of this type can consist, forexample, of magnesium diecasting.

A further advantage of the invention can be seen in the fact that theconstruction is very simple because no additional measures are necessaryin order to ensure that the airbag deploys reliably. On the contrary,existing parts of the backrest are used in order to bring this about.Accordingly, the arrangement according to the invention of the airbagmodule in the backrest ensures that the airbag is deployed or emergesconsiderably more reliably.

According to one embodiment, the airbag module has a housing which atleast partially surrounds the airbag, for example in the rear region andin the side regions. Since the housing does not completely surround theairbag module, it therefore has a relatively wide opening. This meansthat the housing provides a relatively small resistance to the deployingairbag thus assisting a reliable deployment.

A plate can be provided in the region in which the housing does notsurround the airbag module. This plate serves, on the one hand, to closethe airbag housing and therefore to provide a certain protection in theinoperative state to the airbag components arranged in the housing.Furthermore, it serves to damp the first thrust of the deploying airbag,with the result that the airbag emerges at a moderate speed. Finally,the plate enables the airbag to emerge. When, during deployment, theairbag presses against the plate, the plate is bent up and pushes thebackrest components, which join the plate, for example the padding, tothe side. For this purpose, the plate is preferably arranged on thatside of the frame which faces away from the outer contour of the seatthat faces the side wall structure.

The plate can be connected on one side fixedly to the frame of thebackrest. When the airbag emerges, this fixed connection forms a hingeabout which the plate moves. However, it is also conceivable for theplate to be connected directly to the airbag housing and for it to bepivoted open from this connection.

The function of the plate may also be fulfilled by other components ofthe backrest. If, for example, the padding is arranged on a paddingsupport, then it is conceivable for this padding support, which islikewise arranged between the padding and airbag module, to take overthe closing, damping and opening.

According to a further embodiment, the frame at least partiallysurrounds the airbag module. The frame preferably surrounds the airbagmodule in the regions in which the housing surrounds the airbag. Thisarrangement enables the airbag to be protected in a particularlyreliable manner against actions from the outside—in particular from therear and from the side, as a result of which damage to the airbag moduleis prevented, ensuring an interference-free deployment of the airbag.This arrangement is therefore particularly advantageous because noadditional elements are necessary in order to achieve this protection.The airbag is simply arranged in structures which are already present.In addition, the frame can serve as a guiding device by being aligned insuch a manner that it predetermines the direction of deployment.

The outlet or the outlet opening for the airbag may be provided, forexample, between the frame and padding. The material combination of arigid frame and elastic padding, which are also coordinated with eachother in terms of their shape, makes it possible for an outlet openingfor an airbag to be provided in a particularly simple manner without theuse of additional components. If the frame and padding are not connectedto each other in the region of the outlet opening, the padding isdeformed, during the deployment of the airbag, by the force which theairbag applies to it, and thereby releases the path for the emergence ofthe airbag. The arrangement according to the invention is visuallyattractive because the opening is not seen. In addition, neither seamsnor other known closure elements are necessary. As a result, firstly, asimple and therefore also cost-effective solution is proposed. Secondly,elements which may obstruct the emergence of the airbag are notprovided.

The outlet opening may be arranged, for example, in that region of themotor vehicle seat which faces the side wall structure. If the directionof deployment points obliquely forward, a particularly advantageouspositioning of the airbag arises during the deployment and in thedeployed state.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be explained in greater detail below with referenceto the exemplary embodiment which is illustrated in the drawing, inwhich:

FIG. 1 shows a side view of a backrest of a motor vehicle seat, as seenfrom the side wall structure;

FIG. 2 shows a section through a side region of the motor vehicle seat,which region faces the side wall structure, together with a safetydevice according to the invention in the inoperative state in accordancewith the line II—II in FIG. 1, and

FIG. 3 shows a section corresponding to FIG. 2 with an activated safetydevice.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a backrest 1 which, together with a seat cushion part(not illustrated), forms a motor vehicle seat. The backrest 1 has a headrestraint 2. The side view reveals a backrest cover 3 which lines therear part of the backrest 1. Also visible is padding 4 which forms thatpart of the backrest 1 which faces forward and enables a driver to sitcomfortably. In the embodiment illustrated, a backrest frame 5 can alsobe seen. This is arranged visibly and forms part of the outer contour ofthe motor vehicle seat. However, it is also conceivable to line abackrest frame of this type in a suitable manner, for example by thebackrest cover 3, which is pulled further forward in the side region ofthe motor vehicle seat, or by padding 4.

An airbag module is arranged in the backrest. This is revealed in FIG. 2which shows a sectional illustration of that region of a backrest 1which faces the motor vehicle side according to the line II—II inFIG. 1. The arrow A points to the rear in the direction of travel andthe arrow B points forward in the direction of travel. The backrestcover 3 is illustrated in the region facing to the rear. In addition tocovering the rear side of the backrest 1, said backrest cover coversparts of those side regions of the backrest 1 which point in thedirection of the side wall structure. That side of the backrest 1 whichfaces forward is formed by the padding 4. This is attached to a paddingsupport 6.

The frame 5 is arranged between the backrest cover 3 and padding 4. Inthe exemplary embodiment illustrated, the backrest cover 3, frame 5 andpadding 4 form the outer contour of the backrest 1. They butt togetherin each case at the points 7 and 8. However, it is also conceivable forthe frame 5 to be arranged in the interior of the backrest 1 and, forexample, to be concealed by the backrest cover 3 and/or padding 4. Inthis case, the padding 4 and backrest cover 3 butt together on the outercontour of the seat.

The frame 5 has an essentially U-shaped cross section, the opening 9 ofwhich is directed forward. An airbag module 11 is arranged in the spacesurrounded by the U-shaped frame 5. The frame 5 therefore extendsbetween the airbag module 11 and the side wall structure of the motorvehicle. The airbag module 11 comprises generally customary componentswhich are not discussed in greater detail at this point. FIG. 2illustrates an airbag housing 12, the cross-sectional shape of which ismatched to that of the frame 5. An opening 13 of the airbag housing 12points in the same direction as the opening 9 of the frame 5, namely inthe direction of travel. The opening 13 of the airbag housing 12 isprovided with a plate 14. The plate 14 is connected to the frame 5 atthat end of the frame 5 which faces away from the outer contour of thebackrest 1. The other end of the plate 14 bears against the airbaghousing 12. The plate 14 is arranged between the airbag module 12 andthe padding 4.

An airbag outlet opening is provided at the point 8, i.e. at the pointat which the backrest frame 5 and padding support 6 butt together. Thebackrest frame 5 and padding 6 are not connected to each other in thisregion. They merely butt against each other and, on account of theirshapes which are matched to each other, form a closed contour. Theairbag outlet opening is thus not visible from the outside. Also,however, no additional elements or structures are necessary in order toclose the opening.

FIG. 3 illustrates a deploying airbag 15. The airbag 15 has alreadypressed the plate 14 outward as it deploys about a pivot axis 16. Theplate 14 has, in turn, moved the padding support 6 together with thepadding 4 attached on it. This results in the formation of an outlet gapor opening b which releases the path for the airbag. Owing to the airbag15 first of all butting against the plate 14, the first pulse of thedeploying airbag 15 is damped. This means that the airbag 15 emerges ata throttled speed. In addition, the plate 14 serves to open up the pathfor the emerging airbag 15. The frame 5 fulfills two tasks in relationto the safety device according to the invention. Firstly, it shields thesafety device against applications of force from the region of the sidewall and thereby prevents the outlet opening from becoming blocked.Secondly, it assists the airbag 15 in deploying in the correctdirection.

1. A safety device for a motor vehicle seat having a seat cushion partand a backrest, the backrest having a rigid frame, a backrest cover,which faces rearward as seen in the direction of travel, and paddingwhich faces forward, as seen in the direction of travel, and an airbagmodule is integrated into the backrest, said airbag module beingarranged in a region of the backrest which faces a side wall structureof the motor vehicle in such a manner that an airbag is deployed whenthere is an impact to the side wall of the motor vehicle, wherein therigid frame surrounds the airbag module in at least a rear region of theairbag module which faces rearward as seen in the direction of traveland a side region of the airbag module which faces the side wallstructure.
 2. The safety device as claimed in claim 1, wherein theairbag module has a housing which at least partially surrounds theairbag in the folded up state.
 3. The safety device as claimed in claim2, wherein the housing surrounds the airbag in a region of the housingwhich faces rearward, as seen in the direction of travel, and in a sideregion of the housing which faces the side wall structure.
 4. The safetydevice as claimed in claim 3, wherein a plate is provided in a region inwhich the housing does not surround the airbag module.
 5. The safetydevice as claimed in claim 4, wherein the plate is connected at least onone side to the frame.
 6. The safety device as claimed in claim 5,wherein an airbag outlet opening is provided between the frame andpadding.
 7. The safety device as claimed in claim 6, wherein the framesand padding are not connected to each other in the region of the airbagoutlet opening.
 8. The safety device as claimed in claim 7, wherein thepadding is of elastic design in the region of the airbag outlet openingin such a manner that it permits the outlet opening to be open when theairbag is deployed.
 9. The safety device as claimed in claim 8, whereinthe airbag outlet opening is arranged in the region of the backrestwhich faces the side wall structure.
 10. The safety device as claimed inclaim 6, wherein the airbag outlet opening is arranged in a side regionof the backrest which faces the side wall structure.
 11. The safetydevice as claimed in claim 6, wherein the padding is of elastic designin the region of the airbag outlet opening in such a manner that itpermits the outlet opening to be open when the airbag is deployed. 12.The safety device as claimed in claim 1, wherein an airbag outletopening is provided between the frame and padding.
 13. A safety devicefor a motor vehicle seat including a seat cushion part, a backresthaving a rigid frame, a backrest cover, which faces rearward as seen inthe direction of travel, and padding which faces forward, as seen in thedirection of travel, the safety device comprising: an airbag moduleincluding an airbag, the airbag module being integrated into thebackrest and arranged in a region of the backrest which faces a sidewall structure of the motor vehicle, wherein a rear region of the airbagmodule which faces rearward as seen in the direction of travel and aside region of the airbag module which faces the side wall structure aresurrounded by the rigid frame.
 14. The safety device as claimed in claim13, wherein the airbag module includes a housing which at leastpartially surrounds the airbag when the airbag is in a folded-up state.15. The safety device as claimed in claim 14, wherein the housingsurrounds the airbag in a rear region of the housing which facesrearward, as seen in the direction of travel, and in a side region ofthe housing facing the side wall structure.
 16. The safety device asclaimed in claim 15, further comprising a plate in a region of theairbag that is not surrounded by the housing of the airbag module. 17.The safety device as claimed in claim 16, wherein the plate is connectedat least on one side to the frame of the seat.
 18. The safety device asclaimed in claim 17, wherein an airbag outlet opening is providedbetween the frame and padding.
 19. The safety device as claimed in claim18, wherein the frame and padding are not connected to each other at theairbag outlet opening.
 20. The safety device as claimed in claim 19,wherein the padding is of elastic design in a region of the airbagoutlet opening in such a manner that it permits the outlet opening to beopen when the airbag is deployed.
 21. The safety device as claimed inclaim 20, wherein the airbag outlet opening is arranged in the region ofthe backrest which faces the side wall structure.
 22. A motor vehicleseat comprising a seat cushion part; a backrest including a rigid frame,a backrest cover, which faces rearward as seen in the direction oftravel, and padding which faces forward, as seen in the direction oftravel, the safety device comprising; an airbag module including anairbag, the airbag module being integrated into the backrest andarranged in a region of the backrest which faces a side wall structureof the motor vehicle, wherein a rear region of the airbag module whichfaces rearward as seen in the direction of travel and a side region ofthe airbag module which faces the side wall structure are surrounded bythe rigid frame.
 23. The motor vehicle seat as claimed in claim 22,wherein the airbag module includes a housing which at least partiallysurrounds the airbag when the airbag is in a folded-up state.
 24. Themotor vehicle seat as claimed in claim 23, wherein the housing surroundsthe airbag in a rear region of the housing which faces rearward, as seenin the direction of travel, and in a side region of the housing facingthe side wall structure.
 25. The motor vehicle seat as claimed in claim24, further comprising a plate in a region of the airbag that is notsurrounded by the housing of the airbag module.
 26. The motor vehicleseat as claimed in claim 25, wherein the plate is connected at least onone side to the frame.
 27. The motor vehicle seat as claimed in claim26, further comprising an airbag outlet opening between the frame andpadding.
 28. The motor vehicle seat as claimed in claim 27, wherein theframe and padding are not connected to each other at the airbag outletopening.
 29. The motor vehicle seat as claimed in claim 28, wherein thepadding is of elastic design in a region of the airbag outlet opening insuch a manner that it permits the outlet opening to be open when theairbag is deployed.
 30. The motor vehicle seat as claimed in claim 29,wherein the airbag outlet opening is arranged in the region of thebackrest which faces the side wall structure.
 31. A method of making asafety device, comprising: integrating an airbag module into a region ofa vehicle seat's backrest which faces a side wall structure of the motorvehicle; and surrounding a rear region of the airbag module which facesrearward as seen in the direction of travel and a side region of theairbag module which faces the side wall structure with a rigid frame ofthe backrest.